Protective mouthguard

ABSTRACT

The present disclosure describes a polymer mouthguard for protecting the teeth of a wearer. The mouthguard includes a lingual portion, a facial portion, and an occlusal portion connected with one another in the shape of an arch and together defining a trough for receiving the upper (maxillary) or lower (mandibular) teeth of a wearer. At least one, or both, of the facial portion and the occlusal portion have a shock absorbing lattice formed therein. The mouthguard can be produced as a single object by the process of additive manufacturing (e.g., stereolithography).

RELATED APPLICATION(S)

The present application is a continuation application of U.S. patentapplication Ser. No. 18/050,229, filed Oct. 27, 2022 which claimspriority from and the benefit of U.S. Provisional Patent ApplicationSer. No. 63/264,512, filed Nov. 24, 2021, the disclosure of which ishereby incorporated herein in its entirety.

FIELD

This invention relates to mouthguards, and particularly relates tomouthguards that can be produced by additive manufacturing techniquessuch as stereolithography that incorporate 3D lattice structures to aidin shock absorption, breathability, and/or saliva drainage.

BACKGROUND

Mouthguards are widely used in sports including boxing, hockey, rugby,American football, soccer, and others to protect the teeth ofparticipants from impact injury. In addition, mouthguards have medicaland dental uses, including protecting the teeth of a wearer duringseizures, and protecting teeth from grinding (bruxism) during sleep(mouthguards for the latter sometimes referred to as night guards).

Adell, U.S. Pat. No. 4,955,393 (Sep. 11, 1990) describes a preformedmouthguard suitable for mass production. The mouthguard has upper andlower troughs that generally conform to the upper and lower dentalarches of a wearer. Liners of impression material are disposed in thetroughs to aid in conforming the preformed mouthguards to the teeth ofan individual wearer. In addition, the body portion has spaced-apartsaliva ducts formed therein, extending in an inner to outer-facingdirection (i.e., lingual to facial/buccal) to aid in draining saliva toenhance the comfort of the mouthguard for a wearer. Inclusion ofchannels in mouthguards to aid in breathing is also known (see, e.g.,Turkbas, U.S. Patent Publication No. 2019/0015726 (Jan. 17, 2019).

Akervall et al. (U.S. Pat. Nos. 9,517,400 and 10,945,874) describepreformed, thermoplastic, polymer mouthguards that can be custom-fittedto a wearer by heating. The mouthguards include perforations to aid infitting, and to aid in air and saliva flow (see also Sisu MouthguardFitting Instructions (2020)).

Currently available mouthguards all have their own set of advantages anddisadvantages, depending on the materials from which they are made, theshapes in which they are formed, and the processes by which they areproduced. There remains a need for new mouthguard designs, and new waysof effectively producing such mouthguards.

SUMMARY

A polymer mouthguard for protecting the teeth of a wearer is describedherein. The mouthguard includes a lingual portion, a facial portion, andan occlusal portion connected with one another in the shape of an archand together defining a trough for receiving the upper (maxillary) orlower (mandibular) teeth of a wearer. At least one, or both, of thefacial portion and the occlusal portion have a shock absorbing latticeformed therein.

In some embodiments, the lingual portion can have a smooth comfortsurface (e.g., an uninterrupted solid surface) formed thereon.

In some embodiments, the mouthguard can be produced as a single objectby the process of additive manufacturing (e.g., stereolithography).

In some embodiments, each shock absorbing lattice can include repeatingunit cells (e.g., forming a strut lattice of interconnected struts andnodes, forming a triply periodic surface lattice, or a combinationthereof).

In some embodiments, both the facial portion and the occlusal portioncan have a shock-absorbing lattice formed therein.

In some embodiments, the shock-absorbing lattice of the facial portion,and/or the shock absorbing lattice of the occlusal portion, can includea conformal lattice.

In some embodiments, the mouthguard can include edge and cornerportions. At least some, or all, of the edge and corner portions can beradiused (e.g., to enhance the comfort, and/or reduce trapping ofsaliva, food particles, etc.).

In some embodiments, the shock absorbing lattice of the facial portionand the shock absorbing lattice of the occlusal portion can differ fromone another (e.g., in lattice unit cell type, lattice strut diameter,lattice strut length, or a combination thereof), to thereby impartdifferent shock-absorbing properties to the occlusal portion and thefacial portion.

In some embodiments, the shock absorbing lattice of the facial portioncan have a stiffness gradient formed therein (e.g., the latticeincreases in stiffness in the facial to lingual direction).

In some embodiments, the shock absorbing lattice of the facial portion,and/or the shock absorbing lattice of the occlusal portion, can includeat least two different energy attenuation regions (e.g., regionsdiffering in impact absorption in the facial to lingual direction, inthe anterior to posterior direction, or a combination thereof).

In some embodiments, the shock absorbing lattice of the facial portion,and/or the shock absorbing lattice of the occlusal portion, can beconfigured to promote the flow of air therethrough during breathing bythe wearer.

In some embodiments, the shock absorbing lattice of the facial portion,and/or the shock absorbing lattice of the occlusal portion, can beconfigured to promote the drainage of saliva therethrough by a wearer.

In some embodiments, the lingual portion, facial portion, and occlusalportion can further define an opposite trough for receiving the opposite(maxillary or mandibular) teeth of a wearer.

In some embodiments, at least one of the facial portion and the lingualportion can include a conforming lattice (that is, by matching the shapeof the wearer's dental arch, by applying securing pressure to the dentalarch of the wearer, or a combination thereof) facing the upper and/orlower trough, the conforming lattice configured to aid in fitting themouthguard to an individual wearer, and/or to aid in retaining themouthguard on the dental arch of the wearer during a sport or athleticactivity.

In some embodiments, the mouthguard can consist essentially of aflexible or elastic polymer.

A computer-implemented method of making a mouthguard is also describedherein. The method includes inputting into a computer a dental arch datafile, the data file produced by the process of scanning at least one, orboth, dental arches of the intended wearer; generating in the computer amouthguard data file from the dental arch data file; and then additivelymanufacturing the mouthguard from the data file.

In some embodiments, the method can further include inputting userpreference data for the intended wearer into the computer, and thenmodifying the generating step and/or the additively manufacturing stepbased on the user preference data.

In some embodiments, the user preference data can include at least one,two, or three different mouthguard characteristics.

In some embodiments, the different mouthguard characteristics can beselected from: stiffness, weight, impact absorption, ease of air flow(breathability), degree of saliva drainage, surface texture, size,and/or mouthguard color.

In some embodiments, the user preference data can include at least twodifferent characteristics. The characteristics can be prioritized, andthe modifying and/or generating steps can be carried out based on theprioritized characteristics, with a characteristic having a lesserpriority being de-emphasized or deleted during the modifying and/orgenerating steps when they are incompatible with a characteristic havinga greater priority.

Angelini et al., U.S. Patent Publication No. 2020/0282639 (Sep. 10,2020) describes methods of making mouthguards by additivemanufacturing/3D printing, but does not suggest incorporating a shockabsorbing lattice therein.

The foregoing and other objects and aspects of the present invention areexplained in greater detail in the drawings herein and the specificationset forth below. The disclosures of all United. States patent referencescited herein are to be incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a non-limiting embodiment of amouthguard of the present invention.

FIG. 2 is a top plan view of the embodiment of FIG. 1 , looking downinto the trough that receives a wearer's teeth.

FIG. 3 is a bottom plan view of the embodiment of FIGS. 1 and 2 ,looking down on the occlusal surface portion.

FIG. 4 is a front view of the embodiment of FIGS. 1-3 .

FIG. 5 is a side view of the embodiment of FIGS. 1-4 .

FIG. 6A is a side sectional schematic view of further embodiment of theinvention, taken along a line corresponding to that of line x-x in FIG.5 .

FIG. 6B is a side sectional schematic view of a still further embodimentof the invention, again taken along a line corresponding to that of linex-x in FIG. 5 .

FIG. 7 is a flow chart illustrating one embodiment of a process asdescribed herein.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention is now described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe scope of the invention to those skilled in the art.

As used herein, the term “and/or” includes any and all possiblecombinations of one or more of the associated listed items, as well asthe lack of combinations when interpreted in the alternative (“or”).

1. Mouthguards

A non-limiting example of a mouthguard as described herein isillustrated in FIGS. 1-5 , with additional variations described in FIGS.6A-6B. Specific configurations of mouthguards as described herein willdepend upon factors such as the age, skill level, size and weight of thewearer, on the specific activity during which the mouthguard is worn,and in some cases on the team position of the wearer. Mouthguards asdescribed herein can be configured or optimized for any of a variety ofsports, including but not limited to: baseball, basketball, BMX cycling,boxing, bull riding, field hockey, football, ice hockey, lacross,martial arts and mixed martial arts (e.g., karate, jiu jitsu, tae kwondo, judo, etc.), motor X, kick boxing, roller derby, rugby, soccer,water polo, weightlifting, etc.

FIGS. 1-5 show a non-limiting example of a polymer mouthguard (10) forprotecting the teeth of a wearer. The mouthguard has a lingual portion(11), and a facial (or buccal) portion (12), and an occlusal portion(15) connected with one another in the shape of an arch and togetherdefining a trough (16) for receiving the upper (maxillary) or lower(mandibular) teeth of a wearer. Anterior (13) and posterior (14)portions are labelled for convenience.

As noted above, at least one, or both, of the facial portion (12) andthe occlusal portion (15) have a shock absorbing lattice (12 a, 15 a)formed therein. In the illustrated embodiment, both the facial andocclusal portions have a shock absorbing lattice (12 a, 15 a) formedtherein. In addition, the lingual portion (11) optionally, butpreferably, has a smooth comfort surface (11 a) (e.g., an uninterruptedsolid surface) formed thereon, better adapated for a comfortable surfaceagainst the tongue of the wearer. And, again, while a solid surface isshown, in some embodiments, the comfort surface can have openingstherein as well, with the openings preferably radiused or smoothlytransitioning to again provide a comfortable (rather than rough) surfaceagainst the tongue of the wearer.

As discussed further below, the shock absorbing lattices (12 a, 15 a)typically comprise repeating unit cells. The unit cells may be in theform of a strut lattice of interconnected struts and nodes, may be inthe form of a triply periodic surface lattice, or a combination thereof.Unit cells of a lattice may be all of one type, or may transition fromone type to another in the lattice, as is known in the art. The latticesare preferably “conformal lattices” where unit cells are shaped to fitwithin the overall contours or boundaries of the object, as is alsoknown in the art.

In some embodiments, the shock absorbing lattice (12 a) of the facialportion (12) and the shock absorbing lattice (15 a) of the occlusalportion (15) differ from one another (e.g., in lattice unit cell type,lattice strut diameter, lattice strut length, or a combination thereof),to thereby impart different shock-absorbing properties to the occlusalportion (15) and the facial portion (12). Again, specific choices willdepend upon the specific sport or activity for which the mouthguard isintended (a representative variety of sports and activities being setforth above).

As shown in FIG. 6A, in some embodiments, at least one (or both) of thefacial/buccal portion (12) and the lingual portion (11) can include aconforming lattice (11 b, 12 b) facing the upper and/or lower trough(16), configured to aid in fitting the mouthguard to the individualwearer, and/or aid in retaining the mouthguard on the dental arch of thewearer during activity (e.g., reduce frequency of mouthguard beingknocked out of place). The conforming lattice (11 b, 12 b) can achievethis goal by matching the shape of the wearer's dental arch, by applyingsecuring pressure to the dental arch of the wearer, or a combinationthereof.

In some embodiments, the shock absorbing lattice of the facial portion(12) has a stiffness gradient formed therein such as exemplified by thetwo different shock absorbing zones (12 a, 12 b) in FIG. 6B. Forexample, the lattice can increase in stiffness in the facial to lingualdirection, in either step-wise fashion as illustrated, or in a smooth(or gradient) transitioning manner. In a similar manner, in someembodiments, the shock absorbing lattice (12 a) of the facial portion(12), and/or the shock absorbing lattice (15 a) of the occlusal portion(15), can comprise at least two different energy attenuation regions(e.g., regions differing in impact absorption in the facial to lingualdirection, in the anterior to posterior direction, or a combinationthereof). Again, specific choices will depend upon the specific sport oractivity for which the mouthguard is intended.

In some preferred embodiments, the shock absorbing lattice (12 a) of thefacial portion (12), and/or the shock absorbing lattice (15 a) of theocclusal portion (15), are configured to promote the flow of airtherethrough during breathing by the wearer. And in some preferredembodiments, the shock absorbing lattice (12 a) of the facial portion(12), and/or the shock absorbing lattice (15 a) of the occlusal portion(15), are configured to promote the drainage of saliva therethrough by awearer. These functions are achieved by the mouthguard shown in theillustrative embodiments, but numerous variations will be readilyapparent to those skilled in the art. For example, if a mouthguardadapted for a particular activity requires a denser (and hence more flowor drainage restrictive) lattice, for shock absorbing purposes in someregions, a more open (and hence less restrictive) lattice can beprovided in other regions.

The mouthguard may be for a single arch (used singly, or in matchedpairs) or may be for both arches as also shown in FIG. 6B. In the lattercase, the mouthguard will further include an additional trough (16′) forreceiving the opposite (maxillary or mandibular) teeth of a wearer.

The illustrated embodiment is provided to emphasize the latticestructures. For many preferred uses, it will be noted that themouthguard includes edge and corner portions, and at least some, or all,of these edge and corner portions are preferably radiused as shown bydashed lines (23) in FIG. 6B to enhance the comfort of the mouthguardfor the wearer, and/or reduce trapping of saliva, food particles, etc.

The specific configuration of the shock absorbing lattices, includingmulti-zone shock absorbing lattices and shock absorbing lattices havingadjacent conforming lattices, can be generated by any suitabletechnique, depending on factors such as the intended user, and thepurpose or activity for which the mouthguard will be worn. Exampletechniques include but are not limited to those set forth in Kabaria andKurtz, U.S. Pat. No. 10,882,255, Mass customization in additivemanufacturing (Jan. 5, 2021); Kabaria and Kurtz, U.S. Patent PublicationNo. 2021/0246959, Lattice transitioning structures in additivelymanufactured products (Aug. 12, 2021); Bologna et al., U.S. PatentPublication No. 2020/0215415, Football helmet with components additivelymanufactured to manage impact forces (Jul. 9, 2020); Kabaria, Kurtz,Sage, Burgess, and Chen, PCT Publication No. WO2021/046376, Cushionscontaining shock absorbing triply periodic lattice and related methods(Mar. 11, 2021).

2. Stock and Customized Mouthguards

The mouthguards described herein can be made in a variety of stock sizes(e.g., extra-small, small, medium, large, extra-large, etc.) adapted fora particular sport. In the alternative, the mouthguards can becustom-fit to a specific wearer.

As schematically shown in FIG. 7 , a custom mouthguard can be producedinputting into a computer a dental arch data file, the data fileproduced by the process of scanning (51) at least one, or both, dentalarches of the intended wearer; then generating (54) in the computer amouthguard data file from the dental arch data file; and then additivelymanufacturing (55) the mouthguard from the data file.

In some embodiments, the method can further include the steps ofinputting into the computer user preference data (52) for the intendedwearer, and then modifying the generating step and/or the additivelymanufacturing step based on the user preference data.

The user preference data may comprise one, two, or three or moredifferent mouthguard characteristics, such as: stiffness, weight, impactabsorption, ease of air flow (breathability), degree of saliva drainage,surface texture, size, and/or mouthguard color. Note also that, when theuser preference data comprises at least two different characteristics,the characteristics can be prioritized (e.g., ranked in priority by theuser), and the modifying and/or generating steps can be carried outbased on the prioritized characteristics, with a characteristic having alesser priority being de-emphasized or deleted during the modifyingand/or generating steps when they are incompatible with a characteristichaving a greater priority.

3. Additive Manufacturing

Mouthguards as described above are preferably produced as a singleobject by the process of additive manufacturing. In this way, themouthguard may consist entirely or essentially of a flexible or elasticpolymer (in some cases, an additional coating such as an antibacterialcoating may be applied).

Techniques for additive manufacturing are known. Suitable techniquesinclude, but are not limited to, techniques such as selective lasersintering (SLS), fused deposition modeling (FDM), stereolithography(SLA), material jetting including three-dimensional printing (3DP), andmultijet modeling (MJM) (MJM including Multi-Jet Fusion such asavailable from Hewlett Packard), and others. See, e.g., H. Bikas et al.,Additive manufacturing methods and modelling approaches: a criticalreview, Int. J. Adv. Manuf. Technol. 83, 389-405 (2016).

SLA methods and apparatus, including bottom-up and top-down versionsthereof, are known and described in, for example, U.S. Pat. No.5,236,637 to Hull, U.S. Pat. Nos. 5,391,072 and 5,529,473 to Lawton,U.S. Pat. No. 7,438,846 to John, U.S. Pat. No. 7,892,474 to Shkolnik,U.S. Pat. No. 8,110,135 to El-Siblani, U.S. Patent Publication No.2013/0292862 to Joyce, and U.S. Patent Publication No. 2013/0295212 toChen et al. The disclosures of these patents and applications areincorporated by reference herein in their entirety.

In some embodiments, the additive manufacturing step is carried out byone of the family of methods sometimes referred to as as continuousliquid interface production (CLIP). CLIP is known and described in, forexample, U.S. Pat. Nos. 9,211,678; 9,205,601; 9,216,546; and others; J.Tumbleston et al., Continuous liquid interface production of 3D Objects,Science 347, 1349-1352 (2015); and R. Janusziewcz et al., Layerlessfabrication with continuous liquid interface production, Proc. Natl.Acad. Sci. USA 113, 11703-11708 (Oct. 18, 2016). Other examples ofmethods and apparatus for carrying out particular embodiments of CLIPinclude, but are not limited to: Batchelder et al., U.S. PatentPublication No. 2017/0129169 (May 11, 2017); Sun and Lichkus, U.S.Patent Publication No. 2016/0288376 (Oct. 6, 2016); Willis et al., U.S.Patent Publication No. 2015/0360419 (Dec. 17, 2015); Lin et al., U.S.Patent Publication No. 2015/0331402 (Nov. 19, 2015); D. Castanon, U.S.Patent Publication No. 2017/0129167 (May 11, 2017). B. Feller, U.S.Patent Publication No. 2018/0243976 (published Aug. 30, 2018); M. Panzerand J. Tumbleston, U.S. Patent Publication No. 2018/0126630 (publishedMay 10, 2018); K. Willis and B. Adzima, U.S. Patent Publication No.2018/0290374 (Oct. 11, 2018) L. Robeson et al., PCT Publication No.WO2019/164234 (see also U.S. Pat. Nos. 10,259,171 and 10,434,706); andC. Mirkin et al., PCT Publication No. WO2017/210298 (see also U.S.Patent Publication No. 2019/0160733).

Any suitable build material or resin can be used (depending upon thespecific additive manufacturing process used) including but not limitedto dual cure resins, Such resins are known and described in, forexample, U.S. Pat. Nos. 9,676,963, 9,453,142 and 9,598,606 to Rolland etal. Particular examples of suitable dual cure resins include, but arenot limited to, Carbon Inc. medical polyurethane, elastomericpolyurethane, rigid polyurethane, flexible polyurethane, and siliconedual cure resins, all available from Carbon, Inc., 1089 Mills Way,Redwood City, Calif. 94063 USA.

After the object is formed, it is typically cleaned (e.g., by washing,centrifgual separation, wiping/blowing, etc., including combinationsthereof), and in some embodiments then further cured, such as by baking(although further curing may in some embodiments be concurrent with thefirst cure, or may be by different mechanisms such as by contacting towater, as described in U.S. Pat. No. 9,453,142 to Rolland et al.).

The foregoing is illustrative of the present invention, and is not to beconstrued as limiting thereof. The invention is defined by the followingclaims, with equivalents of the claims to be included therein.

We claim:
 1. A polymer mouthguard for protecting the teeth of a wearer,comprising: a lingual portion, a facial portion, and an occlusal portionconnected with one another in the shape of an arch and together defininga trough for receiving the upper (maxillary) or lower (mandibular) teethof a wearer; wherein at least one, or both, of said facial portion andsaid occlusal portion have a shock absorbing lattice formed therein. 2.The mouthguard of claim 1, wherein said lingual portion has a smoothcomfort surface formed thereon.
 3. The mouthguard of claim 1, whereinsaid mouthguard is produced as a single object by the process ofadditive manufacturing.
 4. The mouthguard of claim 1, wherein each saidshock absorbing lattice comprises repeating unit cells.
 5. Themouthguard of claim 1, wherein both said facial portion and saidocclusal portion have a shock-absorbing lattice formed therein.
 6. Themouthguard of claim 1, wherein said shock-absorbing lattice of saidfacial portion, and/or said shock absorbing lattice of said occlusalportion, comprises a conformal lattice.
 7. The mouthguard of claim 1,wherein said mouthguard includes edge and corner portions, wherein atleast some, or all, of said edge and corner portions are radiused. 8.The mouthguard of claim 1, wherein said shock absorbing lattice of saidfacial portion and said shock absorbing lattice of said occlusal portiondiffer from one another, to thereby impart different shock-absorbingproperties to said occlusal portion and said facial portion.
 9. Themouthguard of claim 1, wherein said shock absorbing lattice of saidfacial portion has a stiffness gradient formed therein.
 10. Themouthguard of claim 1, wherein said shock absorbing lattice of saidfacial portion, and/or said shock absorbing lattice of said occlusalportion, comprise at least two different energy attenuation regions. 11.The mouthguard of claim 1, wherein said shock absorbing lattice of saidfacial portion, and/or said shock absorbing lattice of said occlusalportion, are configured to promote the flow of air therethrough duringbreathing by the wearer.
 12. The mouthguard of claim 1, wherein saidshock absorbing lattice of said facial portion, and/or said shockabsorbing lattice of said occlusal portion, are configured to promotethe drainage of saliva therethrough by a wearer.
 13. The mouthguard ofclaim 1, wherein said lingual portion, facial portion, and occlusalportion further define an opposite trough for receiving the opposite(maxillary or mandibular) teeth of a wearer.
 14. The mouthguard of claim1, wherein at least one of said facial portion and said lingual portionincludes a conforming lattice facing said upper and/or lower trough, theconforming lattice configured to aid in fitting said mouthguard to anindividual wearer, and/or to aid in retaining the mouthguard on thedental arch of the wearer during a sport or athletic activity.
 15. Themouthguard of claim 1, wherein said mouthguard consists essentially of aflexible or elastic polymer.
 16. A computer-implemented method of makinga mouthguard of claim 1, comprising the steps of: inputting into acomputer a dental arch data file, the data file produced by the processof scanning at least one, or both, dental arches of the intended wearer;generating in the computer a mouthguard data file from said dental archdata file; and then additively manufacturing the mouthguard from saiddata file.
 17. The method of claim 16, further comprising: inputtinguser preference data for the intended wearer into the computer, and thenmodifying said generating step and/or said additively manufacturing stepbased on said user preference data.
 18. The method of claim 17, whereinsaid user preference data comprises at least one, two, or threedifferent mouthguard characteristics.
 19. The method of claim 18,wherein said different mouthguard characteristics are selected from:stiffness, weight, impact absorption, ease of air flow (breathability),degree of saliva drainage, surface texture, size, and/or mouthguardcolor.
 20. The method of claim 18, wherein said user preference datacomprises at least two different characteristics, wherein saidcharacteristics are prioritized, and wherein said modifying and/orgenerating steps are carried out based on said prioritizedcharacteristics, with a characteristic having a lesser priority beingde-emphasized or deleted during said modifying and/or generating stepswhen they are incompatible with a characteristic having a greaterpriority.